Topical morphine significantly reduces pain after PRK without adverse effects

J Refract Surg. 2010;26(12):934-941.

Issue: February 10, 2011

Topical morphine 0.5% minimized pain without hindering recovery after PRK, a study found.

"This approach may provide a safe and effective alternative to the current methods of pain control after ocular surgery and in patients with ocular inflammation," the study authors said.

The prospective, double-blind study included 20 patients who underwent PRK and received 0.5% morphine drops and 20 patients who underwent PRK and received a vehicle control.

Patients were directed to instill drops every 2 hours postoperatively on the day of surgery, then four times daily for 1 to 3 days after surgery. Patients completed pain assessment questionnaires. Follow-up examinations were conducted daily for 4 days postoperatively, weekly for 4 weeks and monthly for 3 months.

Study results showed that the morphine group had statistically significantly lower average and maximum pain scores than the vehicle control group for 4 days postoperatively (P < .05). The morphine group had a maximum pain score of 56.89, and the vehicle control group had a maximum score of 73.62.

Healing of endothelial defects and resolution of corneal haze were similar in the morphine and vehicle control groups, the authors reported.

Postoperative strategies for mitigating pain after surface ablation are quite varied. Diluted topical morphine is a seemingly safe and effective choice for pain management after PRK. Dr. Faktorovich has pioneered work in this area and her results suggest that 0.5% topical morphine provides subjective improvement without prolonged re-epitheliazation or haze induction. Further studies are needed on safety with confocal and specular microscopy and efficacy. This novel approach to postoperative pain management may be useful for epithelial removal in collagen cross-linking and persistent or severe ocular surface disorders.

– George O. Waring IV, MD
Medical Director, Division of Ophthalmology, St. Joseph’s Translational Research Institute, Atlanta
Disclosure: No products or companies are mentioned that would require financial disclosure.